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Re: ISSUE-148: IRIs do *not* always denote the same resource

From: Guus Schreiber <guus.schreiber@vu.nl>
Date: Sun, 22 Dec 2013 19:45:46 +0100
Message-ID: <52B7335A.9050507@vu.nl>
To: David Booth <david@dbooth.org>
CC: Public RDF comments list <public-rdf-comments@w3.org>
David,

I did a quick straw poll in the WG. Two people are in favor of the 
change you propose, but there is also considerable push back.  The 
chairs see insufficient reason to reopen this editorial issue, taking 
into account the extensive discussion that already took place.

I'm still willing to see whether a statement in the spirit of your 
comment can be added to the Primer, but that is all I can offer.

Please let me know whether you can live with this response. If so, 
please answer with [RESOLVED] in the subject line.

Best,
Guus

On 19-12-13 22:33, Guus Schreiber wrote:
> Hi David,
>
> I'm sorry it has gone this way. I don't like the fact that non-members
> cannot subscribe to a group's mailing list either (in earlier groups I
> chaired we had that mechanism, which was a big plus).  But as a group we
> have no control over that.
>
> The fact that the issue was not discussed at some length during the last
> telecon is my doing as chair. Basically, we had an overfull agenda and
> for this issue there were already 60+ messages recorded. I felt we had
> reached the point were further discussion was not of much use.
>
> W.r.t. your petition: I will suggest to the WG to do a straw poll on this.
>
> Thanks for the time you invested in this.
>
> Best,
> Guus
>
>
> On 19-12-13 21:26, David Booth wrote:
>> On 12/18/2013 09:33 PM, David Booth wrote:
>>> On 12/18/2013 05:47 PM, Guus Schreiber wrote:
>>>> David,
>>>>
>>>> The RDF WG resolved today [1] ISSUE-148:
>>>>
>>>  > Resolve ISSUE-148 by changing the "IRIs have global scope"
>>>  > bullet point in section 1.3 in Concepts to "By design,
>>>  > IRIs have global scope. Thus, two different appearances
>>>  > of an IRI denote the same resource. Violating
>>>  > this principle constitutes an IRI collision
>>>  > [WEBARCH]." http://www.w3.org/TR/webarch/#URI-collision
>>>  >
>>>  > We very much hope you can live with this outcome. It might
>>>  > not be exactly what you wanted, but I hope it is at least
>>>  > very close to it.
>>>
>>> Indeed, this is close, but it still does not address my concern,
>>> because it still says "two different appearances of an IRI
>>> denote the same resource" as though that is always true, in
>>> spite of fact that the next sentence acknowledges that this
>>> can be violated (though it gives no clue about how).
>>>
>>> I gather that someone didn't like the word "should" or the
>>> phrase "is intended to" that were proposed earlier.   As a
>>> compromise, how about inserting "RDF assumes that":
>>>
>>>    "By design, IRIs have global scope. Thus, RDF assumes
>>>    that two different appearances of an IRI denote the same
>>>    resource. Violating this principle constitutes an IRI
>>>    collision [WEBARCH]."
>>>    http://www.w3.org/TR/webarch/#URI-collision
>>>
>>> David
>>
>> P.S. According to the meeting minutes,
>> http://www.w3.org/2013/12/18-rdf-wg-minutes.html#item05
>> the WG **did not even consider** any wordings that would have fully
>> addressed the concern that caused me to raise this issue.  The only two
>> options that were considered were *identical* in still having the
>> problem described above.
>>
>> I know it isn't easy to craft verbiage that is acceptable to many
>> different parties with different perspectives, and I have offered to
>> help do that.  But the way the working group has handled this --
>> simultaneously prohibiting discussion on the public-rdf-comments list
>> while also prohibiting non-member subscription to the working group
>> discussion list -- has left me only an extremely blunt instrument for
>> communicating with the working group.  In essence, all I can do is raise
>> a formal objection.  And friends, that's rather broken.  It sure ain't
>> very efficient.
>>
>> This is the time to get this fixed.  We should not go another 5 years
>> with wrong/misleading statements about the uniqueness of IRI reference,
>> leading new RDF users down a garden path only to be surprised and
>> disappointed later when merged graphs don't work as expected.  One might
>> assume that, because this text is a non-normative introduction, it isn't
>> very important.  But it *is* important because it affects how the reader
>> thinks about the whole specification.  Readers need to know that URI
>> collisions can happen **even with RDF that is 100% compliant with the
>> RDF specification**.
>>
>> The currently adopted verbiage *almost* addresses my concern, because it
>> acknowledges that the principle of unique URI reference *can* be
>> violated.  But alas, as currently phrased, readers are likely to assume
>> that such violations are violations of the RDF specifications, rather
>> than violations of a higher level architectural objective.  Readers need
>> to know that RDF makes the *assumption* of unique URI reference, and
>> hence if this assumption is violated, there may be problems due to URI
>> collision.
>>
>> I have spent a *lot* of time over the past several years -- probably
>> *thousands* of hours cumulatively -- trying to get to the bottom of the
>> resource identity issue.  In fact, I may have spent more time on this
>> issue than all other members of the RDF working group *combined*,
>> excluding Pat Hayes!  But that is mere idle speculation.  The point is
>> that although this may seem like a trivial issue to some, it is
>> important to me, as to my mind it ultimately underlies nearly
>> *everything* we do in the Semantic Web that we're trying to build.
>>
>> I have done my best to work as efficiently as possible with the RDF
>> working group -- moving lengthy discussions to other lists, trying hard
>> to reach common understanding with other individuals before proposing
>> fixes that might reach consensus, and offering to help craft acceptable
>> wording -- but as explained above, the constraints imposed by the
>> working group have made the process frustratingly difficult and awkward.
>>
>> So, I guess I will rephrase my suggestion above.  Would anyone strongly
>> *object* to inserting "RDF assumes that" in the currently adopted bullet
>> phrasing, as described above?  If so, why?
>>
>> Thanks,
>> David
>>
>>
Received on Sunday, 22 December 2013 18:46:16 UTC

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